BoilerFaultCodesPotterton E85739 Fault Code
The Potterton E85739 fault code means: your boiler is unable to light the flame because the ignition system is faulty or damaged, leaving you without heating and hot water.. It appears on 1 Potterton model in our database.
Technical description: Ignition Electrode & leadc/w Gasket & 2 screws
What causes the Potterton E85739 fault?
This fault occurs when the boiler's spark system fails to create the flame needed to produce heat. The most common reasons are that the ignition electrode has become worn or soot-covered over time, or the high-voltage lead connecting it to the control board has developed a fault.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Potterton models that show the E85739 fault code
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Source
Potterton E85739 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026